Creating the Basic Application Environment

     Bringing GIS to the Internet is not as simple as generating some images, writing some HTML code and uploading it to a server. The web, as we know it, is not well-suited to the level of dynamic environment required. The web is, primarily, a static environment. To overcome this limitation, a separate environment, working in parallel with the web, is required. This environment is ESRI’s ArcIMS.

     ArcIMS is an Internet Mapping Server. IMS allows existing GIS data to be published interactively on the web. According to ESRI, “IMS also does something that no other Web-based mapping solution [MapQuest, Yahoo! Maps, etc.] can: it enables true distribution of GIS applications on the Web.” ArcIMS operates in a distributed computing environment; a client (the end-user at their home or office computer) requests information from an Internet or Intranet server. The server then processes the request and sends the information back to the client viewer.

     ArcIMS allow the integration and presentation of data from multiple sources. Locally stored shapefiles, coverages and ArcSDE layers can be combined with web-located data for localized query and analysis. The resulting presentation can be used as-is, in its default state, or can be highly customized and tailored to the individual project’s needs.

     ArcIMS integrates all the tools required to define, design, host and manage the site. This suite of tools is discussed in detail below.

Applications Used

ArcIMS

     ArcIMS, and its various components, was the main application used in the creation of the application site. The term “components” is used as ArcIMS is more of a suite of programs that work with one another rather than one standalone application. Although these programs, Author, Designer and Administrator are all available as standalone Windows (and UNIX) applications, one program, ArcIMS Manager, brings them all together in one web-based interface. Manager also allows remote site management. Our application site was created using the tools provided in ArcIMS Manager, but it could easily have been designed using the tools independently of one another.

     The first step in authoring a map and publishing it on the Internet is creating a MapService. “A MapService allows the content of a map configuration file to be published on the Internet and sets the framework for the web site’s functionality.” (ESRI, Using ArcIMS 3.1, 39). These configuration files, or .axl files, are structured text files, written in ArcXML, that “define content for MapServices and is used for requests and responses between clients… and servers.” (ESRI, 149). MapService configuration files are set up in ArcIMS Author.

     Author’s interface is somewhat similar to that of ArcView GIS. Author allows for data (in ArcView shapfile, ArcInfo coverage or ArcSDE layer format) to be added. Like ArcView, Author sports a legend containing entries for each layer added. Right-clicking on each layer presents a menu full
of options, including a Layer Properties option. The properties dialog box allows the user to change the name of the layer, set legend (colour, shading, stoke pitch, etc.) and label (font, size, positioning, style, etc.) options and change scale range settings. Author also allows the user to configure scale bar settings (screen and map units).

     Author also allows the user to add MapTips to any layers present in the MapService. A MapTip is a text box that appears when the user hovers the mouse pointer over a feature on the map. Our application makes extensive use of MapTips; when a user hovers the mouse pointer over a University building on the map, for example, a MapTip appears that displays the name and abbreviation of that building (i.e.“Academic Quadrangle (AQ)”). One field per layer can be defined as that layer’s MapTip. This created a problem for our application. The building layer, for example, has separate fields for the building name and the building abbreviation; we used the concatenate function in Excel to create a MapTip field that combines the required two fields. Creating the MapTip for the viewpoint layer required concatenating four separate fields along with several text strings.

     Once the data is imported and all customizations have been completed, the settings are saved to an .axl file. The output of the MapService configuration file for our application, sfu.axl, is provided in Appendix C. This .axl file can be edited in a text editor for further configuration, if required. For example, we edited sfu.axl in order to change the colours of the proposed building layers after the original file had been created in Author.

     The final step in creating the application is designing the website. This is accomplished in ArcIMS Designer, a wizard-based program that sets the parameters for the look and feel of the website. Designer allows the site administrator to set the following parameters:

• Adding a MapService (the file created in Author);

• Choosing between the HTML and Java Viewers (see below);

• Choosing the site template (see below);

• Choosing colours;

• Setting the map scale and extent;

• Choosing what layers are or are not visible;

• Defining the overview map, if used (we did not use an overview map);

• Setting scale bar options;

• Choosing what tools are provided to the user;

• Setting MapTips;

• Setting the final location (directory) for the website.

The two most important decisions that need to be made while using Designer are:
     a) what viewer to use (HTML or Java) and
     b) what template to use (HTML, Java Standard or Java Custom).

     The Viewer screen in designer offers the administrator up to two choices of viewers: HTML Viewer and Java Viewer. The HTML Viewer, a simple, server-side interface that offers limited functionality, is only available if the chosen MapService consists of one Image MapService. If this is not the case, the HTML Viewer option will appear grayed out and the only choice available will be the Java Viewer. The Java Viewer allows for more functionality, live streaming of data, and more customization. Using the Java Viewer necessitates the end user to download and install extra software to their PC – a Java runtime environment, or JRE, and the ArcIMS viewer software are both required for complete and proper functionality. Our application uses the Java Viewer.

     After choosing the viewer, the administrator has to choose what template to base their site design on. If the site uses the HTML Viewer, the only choice given is the HTML template. If the site, like ours, uses the Java Viewer, there are two possible choices: Java Standard and Java Custom. The standard template includes all possible tools, a toolbar across the top of the screen, and does not allow for customization. The custom template offers a toolbar along the left side of the page, a choice of which tools are provided to the user, and full customization of the site using HTML and JavaScript. The UniverCity application uses the custom template. Most of the site has been changed from its stock state; these customizations are elsewhere in this report.

     After all choices have been made, Designer writes the necessary files to the specified directories and the site is ready for use or further customization.

     The final ArcIMS application is ArcIMS Administrator. Administrator offers many of the same features as the administration section of Manager, but in a standalone application. Administrator (and Manager) offers the following functionality:

• Starting and stopping MapServices;

• Opening and refreshing a site (for making changes to the legend, for example);

• Creating a new MapService;

• Saving the site configuration;

• Deleting a MapService;

• Managing Virtual Servers and folders.

ArcView GIS

     ArcView GIS is a desktop GIS application developed by ESRI. ArcView was used to manipulate and prepare the data for our application. We used it to:

• Add attribute data to the basic shapfiles, such as building name, viewpoint elevation, etc.

• Remove extraneous data, such as spurious polygons.

• Create the TIN models and viewshed maps, using the 3D Analyst module.

ArcInfo Workstation & ArcEdit

     ArcInfo is the comprehensive GIS that allows us to do numerous geoprocessing work like projecting and transforming our dataset. ArcEdit is the sub environment in ArcInfo which allows us to do the editing and digitizing of the ArcInfo coverages.

ArcCatalog

     This ArcGIS application allows us to convert the dataset format between ArcInfo coverages and ArcView shapefiles and vice versa. The application works functions like a “Windows Explorer” for GIS data; it allows the user to manage their data.

Microsoft Excel

     Microsoft Excel was used to make a variety of modifications to the dataset. It was used to add fields to shapefiles, convert the case of the URLs in viewpoints.dbf from uppercase to lowercase, create the MAPTIP fields (using the concatenate function to combine several fields into a new single field).

FileMaker Pro

     FileMaker Pro is a relational database program. While adding attributes to the SFU Buildings layer, the .dfb file was damaged. There were more entries in the attribute table than in the shapefile index. Rather than start entering attributes all over again, we took a backup copy of the shapefile (with empty NAME and ABBR fields), imported it into FileMaker, linked it to the damaged copy, and using the polygon ID field as a key, we pulled the NAME and ABBR fields from the damaged file to the new, clean copy. The database was exported to a tab-delimited text file. That file was then opened in Excel and saved as a dBase IV (.dbf) file. ArcView was properly able to open the final .dbf file.

VR Worx

     VR Worx was used to create the 360º panoramic views that accompany the application site. These views use a technology called QuickTime Virtual Reality, or QTVR. A QTVR panorama is a series of still images that are “stitched” together to create a single long image of a given scene. That image is then “wrapped” around to create a 360º circle. When viewed, the QTVR movie gives the effect of standing in one place and turning one’s body in a complete circle.We used a Kodak DC3400 digital camera to capture between 10 and 21 images for each of our viewpoints. With the camera mounted on a tripod, we simply took a series of pictures around the tripod’s rotational axis, trying to achieve approximately 50% overlap in each image. In all, we ended up with approximately 315 images.

     Once the images had been downloaded and captured, we used VR Worx to create the panoramas. A template was created that had presets for the focal length of the camera’s lens, angle of view and over-lap. The program took the images from each viewpoint, stitched them together to form the panoramic image, blended them together and compressed and created the final movie file. The resulting files range in size from 350 kb to 1.5 MB in size.

Miscellaneous Software

     Other software used for the application site included: Adobe GoLive, Adobe Illustrator, Adobe Photoshop, BBEdit and Macromedia Freehand.